netcls_cgroup: move config inheritance to ->css_online() and remove .broken_hierarchy marking

It turns out that we'll have to live with attributes which are
inherited at cgroup creation time but not affected by further updates
to the parent afterwards - such attributes are already in wide use
e.g. for cpuset.

So, there's nothing to do for netcls_cgroup for hierarchy support.
Its current behavior - inherit only during creation - is good enough.

Move config inheriting from ->css_alloc() to ->css_online() for
consistency, which doesn't change behavior at all, and remove
.broken_hierarchy marking.

Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-and-Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Acked-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 12 deletions

diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 8cdc18e075fb..31f06b633574 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -41,11 +41,15 @@ static struct cgroup_subsys_state *cgrp_css_alloc(struct cgroup *cgrp)
         cs = kzalloc(sizeof(*cs), GFP_KERNEL);
         if (!cs)
                 return ERR_PTR(-ENOMEM);
+        return &cs->css;
+}
 
+static int cgrp_css_online(struct cgroup *cgrp)
+{
         if (cgrp->parent)
-                cs->classid = cgrp_cls_state(cgrp->parent)->classid;
-
-        return &cs->css;
+                cgrp_cls_state(cgrp)->classid =
+                        cgrp_cls_state(cgrp->parent)->classid;
+        return 0;
 }
 
 static void cgrp_css_free(struct cgroup *cgrp)
@@ -76,19 +80,11 @@ static struct cftype ss_files[] = {
 struct cgroup_subsys net_cls_subsys = {
         .name           = "net_cls",
         .css_alloc      = cgrp_css_alloc,
+        .css_online     = cgrp_css_online,
         .css_free       = cgrp_css_free,
         .subsys_id      = net_cls_subsys_id,
         .base_cftypes   = ss_files,
         .module         = THIS_MODULE,
-
-        /*
-         * While net_cls cgroup has the rudimentary hierarchy support of
-         * inheriting the parent's classid on cgroup creation, it doesn't
-         * properly propagates config changes in ancestors to their
-         * descendents.  A child should follow the parent's configuration
-         * but be allowed to override it.  Fix it and remove the following.
-         */
-        .broken_hierarchy = true,
 };
 
 struct cls_cgroup_head {